Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 6 Jun 2001 10:19:34 -0400 (EDT)
From:      Mikhail Teterin <mi@aldan.algebra.com>
To:        current@freebsd.org
Cc:        phk@freebsd.org
Subject:   mdconfig and _virtual_ memory
Message-ID:  <200106061419.f56EJYN18798@aldan.algebra.com>

next in thread | raw e-mail | index | archive | help
Hi!

For years of  using MFS I presumed,  that it used virtual  memory -- RAM
and swap to store the file system -- using RAM for speed of MFS and swap
when RAM was needed by others.

When I moved  to mdconfig, I figured  I have to use ``-t  swap'' for the
same effect, but it seems, I was wrong -- apparently, ``swap'' means the
filesystem will always hit  the disk, even if there is  plenty of RAM to
go around. My suspicion was further confirmed, by disabling the swapping
at  all --  the  mdconfig-ed  device stopped  working  -- disklabel  got
ENOMEM.

Now I use  ``-t malloc'', but I  suspect, this will never  hit the disk,
even if there is where to swap and more memory can be used elsewhere. It
seems, ``-t malloc'' simply bites a chunk of RAM away...

Is it  possible to make md-devices  backed by _virtual memory_?  Did the
old MFS do that? Where else am I wrong in this letter?

Thanks! Yours,

	-mi

P.S. Where is that new mount_mfs wrapper?

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200106061419.f56EJYN18798>